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S Sato

Publications and source records attributed to S Sato.

At least 217 records · Page 12Linked to original sources
PubMed2001

Prevalence of deep venous thrombosis in the lower limbs and the pelvis and pulmonary embolism in patients with positive antiphospholipid antibodies.

BACKGROUND: Antiphospholipid antibodies (AA) are immunoglobulins that cross-react with phospholipid on cell membrane, and are therefore associated with a hypercoagulable state manifested by arterial/venous thromboses. We aimed to determine the prevalence of deep venous thrombosis in the lower limbs and the pelvic region (DVT) and pulmonary embolism (PE) in patients with positive AA. METHODS: Sixty-six patients (48 female, 18 male) with positive lupus anticoagulant (LA) and/or positive anticardiolipin antibody (aCL) underwent radionuclide (RN) venography with 370 MBq of 99mTc-MAA. Pulmonary perfusion scintigraphy was performed in 58 patients. Fifteen patients had positive LA and positive aCL (LA+/aCL+), 33 patients had positive LA only (LA+/ aCL-) and 18 patients had positive aCL only (LA-/aCL+). 43 patients were diagnosed with primary antiphospholipid syndrome (APS) and 19 were diagnosed with APS associated with SLE. RESULTS: DVT was detected in 21 of 66 patients (32%). Patients with LA+/aCL+ showed higher prevalence of DVT (53%) as compared to LA+/aCL- (27%) and LA-/aCL+ (22%). PE was found in 13 of 58 patients (22%). The prevalence of PE was higher in patients with positive aCL (33% in LA+/aCL+; 36% in LA-/aCL+) than in patients with negative aCL (10%). CONCLUSION: Because of the high prevalence of DVT and PE in patients with AA, RN scintigraphy must be recommended in screening for these clinical troubles. These results indicate that the prevalence of DVT and PE may vary in subgroups of AA.

Adolescent↗
PubMed2001

Inhibition of P-selectin specific cell adhesion by a low molecular weight, non-carbohydrate compound, KF38789.

OBJECTIVE AND DESIGN: P-selectin is a cell adhesion molecule of the selectin family. This study evaluated the effects of novel, low molecular weight P-selectin inhibitors in a cell adhesion assay and a murine model of peritonitis. MATERIALS: U937 or HL60 was used for cell adhesion assay. Human polymorphonuclear cells were studied for the production of superoxide. BALB/c mice were used for the in vivo study. TREATMENT: The thioglycollate (TG)-induced accumulation of leukocytes in mice was measured 6 h after the treatment. KF38789 or antibody (1 mg/kg) was injected intravenously prior to TG injection and at 3 h following initial injection. RESULTS: Low molecular weight, non-carbohydrate inhibitors against P-selectin- mediated cell adhesion were tested. One of the most potent inhibitors, KF38789, inhibited the binding of U937 cells to immobilized P-selectin immunoglobulin G chimeric protein (P-selectin-Ig) with an IC50 value of 1.97 microM. Cell adhesion to both E-selectin-Ig and L-selectin-Ig were not affected even by 100 microM of KF38789. Moreover, KF38789 inhibited P-selectin-induced superoxide production from human polymorphonuclear cells. Intravenously injected KF38789 significantly inhibited the TG-induced accumulation of leukocytes in the mouse peritoneal cavity (p<0.01). CONCLUSION: A novel low molecular weight compound, KF38789, specifically inhibited P-selectin-dependent cell adhesion and the leukocyte recruitment in mouse peritonitis.

Animals↗
PubMed2001

Analysis of models for crustacean stretch receptors.

The mechanisms underlying the diverse responses to step current stimuli of models [Edman et al. (1987) J Physiol (Lond) 384: 649-669] of lobster slowly adapting stretch receptor organs (SAO) and fast-adapting stretch receptor organs (FAO) are analyzed. In response to a step current, the models display three distinct types of firing reflecting the level of adaptation to the stimulation. Low-amplitude currents evoke transient firing containing one to several action potentials before the system stabilizes to a resting state. Conversely, high-amplitude stimulations induce a high frequency transient burst that can last several seconds before the model returns to its quiescent state. In the SAO model, the transition between the two regimes is characterized by a sustained pacemaker firing at an intermediate stimulation amplitude. The FAO model does not exhibit such a maintained firing; rather, the duration of the transient firing increases at first with the stimulus intensity, goes through a maximum and then decreases at larger intensities. Both models comprise seven variables representing the membrane potential, the sodium fast activation, fast inactivation, slow inactivation, the potassium fast activation, slow inactivation gating variables, and the intra cellular sodium concentration. To elucidate the mechanisms of the firing adaptations, the seven-variable model for the lobster stretch receptor neuron is first reduced to a three-dimensional system by regrouping variables with similar time scales. More precisely, we substituted the membrane potential V for the sodium fast activation equivalent potential Vm, the potassium fast inactivation Vn for the sodium fast inactivation Vh, and the sodium slow inactivation Vl for the potassium slow inactivation Vr. Comparison of the responses of the reduced models to those of the original models revealed that the main behaviors of the system were preserved in the reduction process. We classified the different types of responses of the reduced SAO and FAO models to constant current stimulation. We analyzed the transient and stationary responses of the reduced models by constructing bifurcation diagrams representing the qualitatively distinct dynamics of the models and the transitions between them. These revealed that (1) the transient firings prior to reaching the stationary state can be accounted for by the sodium slow inactivation evolving more slowly than the other two variables, so that the changes during the transient firings reflect the bifurcations that the two-dimensional system undergoes when the sodium slow inactivation, considered as a parameter, is varied; and (2) the stationary behaviors of the models are captured by the standard bifurcations of a two-dimensional system formed by the membrane potential and the potassium fast inactivation. We found that each type of firing and the transitions between them is due to the interplay between essentially three variables: two fast ones accounting for the action potential generation and the post-discharge refractoriness, and a third slow one representing the adaptation.

Animals↗
PubMed2001

Anti-arthritic effects of KF20444, a new immunosuppressive compound inhibiting dihydroorotate dehydrogenase, on rat collagen-induced arthritis.

OBJECTIVE AND DESIGN: A newly synthesized inhibitor of pyrimidine de novo biosynthesis, KF20444 (6,7-dihydro-10-fluoro-3-(2-fluorophenyl)-5H-benzo [6,7] cyclohepta [1,2-b] quinoline-8-carboxylic acid), was evaluated as an inhibitor of dihydroorotate dehydrogenase (DHO-DHase) and tested in the rat collagen-induced arthritis (CIA) model. MATERIAL AND METHODS: Female Sprague Dawley rats, 5 weeks-old, were used for evaluation of KF20444 in the CIA model. Arthritis was evaluated by arthritis score, serum anti-type II collagen antibody titer, body weight loss, radiographical and histological changes. TREATMENT: KF20444 was orally administered 5 times per week (0.3, 1, 3 mg/kg/day). RESULTS: KF20444 inhibited rat liver dihydroorotate dehydrogenase in vitro with Ki = 8.5 +/- 3.2 nM, which was a comparable effect to that of brequinar sodium (Ki = 25.3 +/- 5.3 nM). The anti-proliferative effect of KF20444 was caused by cell cycle arrest at the S-phase. Treatment with 3 mg/kg/day of KF20444 completely prevented the development of CIA based on reduction of the arthritis score. The 50% effective dose (ED50) of KF20444 on arthritis score was 0.64 mg/kg. KF20444 ameliorated body weight loss associated with disease onset. The compound also inhibited the increase in serum anti-type II collagen antibody level, and reduced both pannus formation and bone erosion. Importantly, KF20444 suppressed the development of arthritis, even when it was administered after booster immunization of collagen. CONCLUSIONS: KF20444 is a novel immunosuppressant which inhibits DHO-DHase and its effects in CIA suggest that it could be useful in the treatment of rheumatoid arthritis.

Animals↗
PubMed2001

Enhanced production of CC-chemokines (RANTES, MCP-1, MIP-1alpha, MIP-1beta, and eotaxin) in patients with atopic dermatitis.

CC-chemokines are potent molecules that direct the migration of leukocytes to inflammatory foci. To determine their role in inflammation associated with atopic dermatitis (AD), we determined serum levels and spontaneous production of CC-chemokines by peripheral blood mononuclear cells (PBMC) in AD patients using an ELISA. Serum levels of RANTES, MCP-1, MIP-1beta, and eotaxin were increased in AD patients (n = 52) compared with normal controls (n = 22). Serum levels of RANTES, MCP-1, and MIP-1beta were increased in AD patients with severe disease (n = 19) compared with normal controls (n = 22). Spontaneous production of RANTES, MCP-1, MIP-1alpha and MIP-1beta by PBMC was augmented in AD patients (n = 39) and in patients with severe AD (n = 14) compared with normal controls (n = 20). Serum RANTES levels correlated with total serum IgE levels, eosinophil numbers, and serum lactate dehydrogenase levels. Our results suggest that augmented production of CC-chemokines correlates with inflammation associated with AD.

Adolescent↗
PubMed2001

Primary non-Hodgkin's lymphoma of the uterine cervix.

We present a patient with primary malignant lymphoma of the uterine cervix, which is extremely rare. She had a complete remission with a combination of chemotherapy and radiotherapy. Measurement of the serum soluble interleukin-2 receptor level was a useful index of the effectiveness of treatment.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Cytokine expression in rat molar gingival periodontal tissues after topical application of lipopolysaccharide.

It is well known that proinflammatory cytokines produced by host cells play an important role in periodontal tissue destruction. However, the localization of the cytokines in in vivo periodontal tissues during development of periodontal disease has not been determined. Immunohistochemical expression of proinflammatory cytokines including IL-1alpha, IL-1beta, and TNF-alpha was examined at 1 and 3 h, and 1, 2, 3, and 7 days after topical application of lipopolysaccharide (LPS; 5 mg/ml in physiological saline) from E. coli into the rat molar gingival sulcus. In the normal periodontal tissues, a small number of cytokine-positive epithelial cells were seen in the junctional epithelium (JE), oral sulcular and oral gingival epithelium, in addition to macrophages infiltrating in the subjunctional epithelial area and osteoblasts lining the alveolar bone surface. Epithelial remnants of Malassez existing throughout periodontal ligament were intensely positive for IL-1beta but negative for the other two cytokines. At 3 h after the LPS treatment, almost all cells in the JE were strongly positive for the cytokines examined. In addition, several cytokine-positive cells, including neutrophils, macrophages, and fibroblasts, were seen in the subjunctional epithelial connective tissue. At day 2, expression of the cytokines in the JE gradually decreased, while cytokine-positive cells in the connective tissue increased in number. Positive staining of the cytokines was seen in osteoclasts and preosteoclasts which appeared along the alveolar bone margin in this period. The number of cytokine-positive cells decreased by day 7. These findings indicate that, in addition to macrophages, neutrophils, and fibroblasts, the JE cells are a potent source of TNF-alpha, IL-1alpha, and IL-1beta reacting to LPS application, and suggest that JE cells may play an important role in the first line of defense against LPS challenge, and the proinflammatory cytokines transiently produced by various host cells may be involved in the initiation of inflammation and subsequent periodontal tissue destruction.

Animals↗
PubMed2001

Variability of the electric organ discharge interval duration in resting Gymnotus carapo.

We recorded the electric organ discharges of resting Gymnotus carapo specimens. We analyzed the time series formed by the sequence of interdischarge intervals. Nonlinear prediction, false nearest neighbor analyses, and comparison between the performance of nonlinear and linear autoregressive models fitted to the data indicated that nonlinear correlations between intervals were absent, or were present to a minor extent only. Following these analyses, we showed that linear autoregressive models with combined Gaussian and shot noise reproduced the variability and correlations of the resting discharge pattern. We discuss the implications of our findings for the mechanisms underlying the timing of electric organ discharge generation. We also argue that autoregressive models can be used to evaluate the changes arising during a wide variety of behaviors, such as the modification in the discharge intervals during interaction between fish pairs.

Animals↗
PubMed2001

Hepatocellular carcinoma depicted as hypoattenuation on CT hepatic arteriography (CTA) and hyperattenuation on CT during arterial portography (CTAP).

We report a 68-year-old man with three nodules of hepatocellular carcinoma (HCC) in a cirrhotic liver; the largest nodule was 3.0cm in diameter. The nodules showed hypoattenuation on computed tomography (CT) hepatic arteriography (CTA) and hyperattenuation on CT during arterial portography (CTAP), indicating that the dominant vascularity of the HCC nodules may have been the portal vein. A biopsy specimen obtained from the nodules showed well differentiated HCC (Edmondson-Steiner grade I). The imaging findings of the nodules on both CTA and CTAP are unusual, in spite of the rather large size, so this seemed suggestive of the hemodynamic properties of relatively large nodules of well differentiated HCC.

Aged↗
PubMed2001

Use of oolong tea extract staining of soft-tissue specimens in low-vacuum scanning electron microscope with a cooling stage.

For direct observation of the surface structures of soft-tissue specimens, we examined rat tracheal tissue in a low-vacuum scanning electron microscope (SEM) equipped with a cooling stage. In specimens fixed with glutaraldehyde and osmium tetroxide, back-scattered electron images of the surface structure could not be clearly observed in the low-vacuum SEM because of the disruption of fine structures and a low signal-to-noise (S/N) ratio. Processing of the specimens in 70% ethanol resulted in marked shrinkage, in contrast to results when processing in 30% ethanol. To overcome these problems, the trachea was initially fixed in 2.5% glutaraldehyde (0.1 M phosphate buffer pH 7.4), treated with a mixture of 0.2% oolong tea extract (OTE) and 2.5% glutaraldehyde, and postfixed in 1% osmium tetroxide. The sample was immersed in 30% ethanol and examined in a chilled SEM at -10 degrees C. The luminal coutour of the tracheal epithelial cells was clearly observed because of the decrease in shrinkage. Cilia of ciliated cells and microvilli of nonciliated cells were also clearly observed. These specimens also showed a high S/N ratio, thus allowing the observation of samples without the need for complete dehydration, critical-point drying, or metal coating. This OTE-incorporated conductive staining method is simple and rapid, and should prove to be highly useful for rapid SEM analyses of biological specimens.

Animals↗
PubMed2001

The protective effect of hepatocyte growth-promoting factor (pHGF) against hydrogen peroxide-induced acute lung injury in rats.

To examine the protective effect of hepatocyte growth-promoting factor (pHGF) in hydrogen peroxide (H(2)O(2))-induced acute lung injury in rats, we observed the pathological changes in lung tissue by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and by light and electron microscopy. We also measured the serum levels of lipid peroxide (LPO). At 6 to 24 h after H(2)O(2) injection, the level of LPO was significantly higher in the H(2)O(2) group than in the H(2)O(2) + pHGF-treated group. This finding indicated that pHGF protected against cell membrane damage in H2O2-induced acute lung injury. Positive TUNEL signals were found in capillary endothelial cells, alveolar epithelial cells, and inflammatory cells. In the H(2)O(2) + pHGF-treated group, TUNEL-positive signals were reduced compared with those in the H(2)O(2) group. This finding indicated that pHGF acts to suppress apoptosis. In the H(2)O(2) group, severe pulmonary edema was seen 3 h after H(2)O(2) injection, and at 24 h, severe atelectasis was seen. In the H(2)O(2) + pHGF-treated group, pulmonary edema was scarcely seen and severe atelectasis was not found. This finding indicated that pHGF acts to suppress both severe pulmonary edema and atelectasis. In the H(2)O(2) group, the formation of subendothelial blebs and disruption of endothelial cells was observed. Edema and disruption were seen in type I epithelial cells. In type II lung epithelial cells, mitochondria were swollen and microvilli had disappeared. In the H(2)O(2) + pHGF-treated group, the formation of subendothelial blebs was seen, but no severe subendothelial blebs were observed. Disruption of capillary endothelial cells and type I epithelial cells was not evident, nor was there damage to type II lung epithelial cells. These findings indicated that pHGF protects the progression of H(2)O(2)-induced acute lung injury, and showed that pHGF acts to stabilize the cell membrane in capillary endothelial cells and lung epithelial cells.

Animals↗
PubMed2001

Effectiveness of a traditional Chinese medicine, Wulingsan, in suppressing the development of nephrocalcinosis induced by a high phosphorus diet in young rats.

The development of nephrocalcinosis in rats fed a high phosphorus diet, and the effectiveness of the Chinese traditional medicine, Wulingsan, and its components (Poria, Alismatis Rhizoma, Atractylodis Rhizoma, Cinnamomi Ramus, Polyporus) in suppressing the development of calcinosis were studied. The rats were fed a high phosphorus diet (1.5% P) supplemented with Wulingsan or its individual components (0.5 g/kg body weight) as separate experimental groups for a 2-week period. Upon histological observation by light microscopy and electron microscopy, signs of nephrocalcinosis were observed in almost all areas of the kidney. Calculi, consisting mainly of needle-shaped crystals of hydroxyapatite, were observed in the proximal tubules, in the collecting ductal lumina, and in the mitochondria of the proximal tubular cells and the interstitial cells. X-ray microanalysis revealed that the calculi were composed of hydroxyapatite (Ca and P). In the group fed the diet supplemented with Wulingsan, the severity of calcinosis in the corticomedullary junction was only slight. In all groups fed individual components of Wulingsan, the severity of calcinosis was almost the same as that in the group fed the high phosphorus diet (1.5% P). Wulingsan suppressed the development of calcinosis in rats fed the high phosphorus diet supplemented with this Chinese medicine, whereas its individual components alone had no effect. The process of calcinosis and the mechanism responsible for the activity of this Chinese medicine in the suppression of calcinosis are discussed.

Animals↗
PubMed2001

Ultrastructural study of the alveolar lining and the bronchial mucus layer by block staining with oolong tea extract: the role of various surfactant materials.

To investigate the roles of various surfactant materials in the lung, we examined rat lung fixed with a mixture of 0.2% oolong tea extract (which contains various polyphenols) and 2.5% glutaraldehyde by electron microscopy. We also measured the surface tension of various isolated surfactant fractions, with a Wilhelm balance. A fraction containing lamellar bodies and a fraction containing lattice-like structures were obtained by discontinuous sucrose gradient centrifugation. From the 15 000 g supernatant, a fraction containing electron-dense amorphous materials was obtained as the 105 g precipitate. The fraction containing lamellar bodies and the fraction containing electron-dense amorphous materials displayed surfactant activity, but the fraction containing lattice-like structures did not. The lamellar bodies were found to be gradually secreted from type II epithelial cells while self-decomposition occurred. The alveolar lining layer had the form of a thin film consisting of electron-dense amorphous materials. These electron-dense amorphous materials may be precursors of the phospholipid film, which exhibits surfactant activity, on the alveolar surface. Lattice-like structures and lamellar bodies were found to be located in the interalveolar pores. The interalveolar pores were filled with surfactant, and this indicated that they do not play a role in the collateral ventilation of the alveoli. It may be that the lattice-like structures serve to connect lung epithelial cells in the interalveolar pores, as well as serving as the basis for the formation of the alveolar ducts. The bronchial mucus layer, which consisted of fibrillar mucous materials, was not divided into an epiphase and a hypophase. A surfactant, in the form of an osmiophilic surface film and some trilaminar materials, was found to cover the mucus layer. Thus, it is possible that the lamellar bodies could be transformed into various surfactant materials, which then serve bronchial or alveolar mechanical and physiological functions.

Animals↗
PubMed2001

Birth of a healthy baby following vitrification of human blastocysts.

OBJECTIVE: To assess vitrification of human blastocysts. DESIGN: Retrospective study of blastocyst vitrification. SETTING: A private clinic. PATIENT(S): Twenty couples with different types of infertility. INTERVENTION(S): Blastocysts were frozen with rapid vitrification and then transferred after thawing. We vitrified blastocysts using a modification of Ishimori's vitrification solution of ethylene glycol and dimethyl sulfoxide (VSED). MAIN OUTCOME MEASURE(S): After thawing, survival was defined by the embryo's development morphology after 6 hours or overnight culture. RESULT(S): Eighteen of 20 patients underwent treatment. Of 45 vitrified blastocysts, 36 survived, for a survival rate of 80% (36 of 45). The implantation rate was 21.9% (7 of 32), and the pregnancy rate (per embryo transfer cycle) was 33.3% (6 of 18). One of the pregnancies resulted in the delivery of a healthy baby. CONCLUSION(S): Supernumerary embryos were grown in culture to blastocysts, and the survival rate of vitrified-thawed blastocysts was the same as that for slow freezing of early stage embryos. Blastocyst vitrification should prove effective for clinical treatment. The present results strongly suggest that this rapid and successful vitrification procedure will replace conventional cryopreservation in the future.

Blastocyst↗
PubMed2001

Birth of healthy twins from in vitro development of human refrozen embryos.

OBJECTIVE: To avoid the risk of ovarian hyperstimulation syndrome and promote pregnancy rate by freezing pronuclear embryos at the oocyte retrieval and using developed refrozen supernumerary embryos in the event of failed pregnancies. DESIGN: A case study. SETTING: Private IVF center. PATIENT(S): Healthy infertile woman undergoing IVF treatment. INTERVENTION(S): Slowly frozen and rapidly refrozen embryos at varying stages of embryonic development were transferred. MAIN OUTCOME MEASURE(S): Survival rate of refrozen and thawed embryos; safety of refrozen embryo transference. RESULT(S): Fertilized pronuclear embryos that were frozen, thawed, and developed to morula embryos were subsequently vitrified, rethawed, and cultured until blastocyst formation before transfer. Healthy fraternal twins were born by caesarian section. The result of transfer was the novel finding of a successful delivery after the use of refrozen embryos. CONCLUSION(S): The transfer of refrozen supernumerary embryos resulted in successful pregnancy and delivery. We will continue to investigate the safety and efficacy of the elective freezing of all embryos as well as their refreezing so that supernumerary embryos can be reused to avoid ovarian hyperstimulation syndrome or in cases of repeated failed pregnancies.

Cryopreservation↗
PubMed2001

Power Doppler signals after percutaneous ethanol injection therapy for hepatocellular carcinoma predict local recurrence of tumors: a prospective study using 199 consecutive patients.

BACKGROUND/AIMS: This study was prospectively conducted to elucidate the relationship between pre-/post-treatment power Doppler signals of hepatocellular carcinoma (HCC) and local recurrence. METHODS: One hundred ninety-nine consecutive patients with 359 HCC lesions receiving percutaneous ethanol injection therapy (PEIT) as a first-line option were enrolled. Arterial power Doppler signals in the tumor were found in 130 nodules, but not detected in 229. After confirmation of complete tumor necrosis on dynamic CT, Doppler signals in nodules were re-evaluated. Patients received periodical examinations to detect HCC recurrence. RESULTS: Local HCC recurrence was observed in 36 lesions; 22%(28/130) of the pretreatment signal positive lesions, in contrast to 3.5% (8/229) of the pretreatment signal negative lesions (P < 0.01). Out of 130 signal positive nodules, signals disappeared in 120 (92%) after PEIT, but were present in ten (8%). During the 25-month follow up, local recurrence was detected in 19 (16%) from the former, in contrast to nine (90%) from the latter (P < 0.001). Uni- and multivariate Cox analysis revealed that the presence of pre-/post-treatment power Doppler signals, histological differentiation and tumor number were independent factors for local recurrence. However, 3-year recurrence rate of new lesions was 51%, but no predictors were identified. CONCLUSIONS: Residual Doppler signals in tumor after PEIT were related to the local HCC recurrence.

Adult↗